diff options
| author | Stefan Hajnoczi <stefanha@redhat.com> | 2020-02-14 17:17:10 +0000 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2020-02-22 08:26:47 +0000 |
| commit | 195ed8cb365edeb0d0a70a2ffdeb7a073f9a8117 (patch) | |
| tree | 5178e83f699e90927825a009012c9ff17047c12c | |
| parent | ca8c6b22754b0f17818b1d1910d31f0aa1a49cc7 (diff) | |
qemu/queue.h: add QLIST_SAFE_REMOVE()
QLIST_REMOVE() assumes the element is in a list. It also leaves the
element's linked list pointers dangling.
Introduce a safe version of QLIST_REMOVE() and convert open-coded
instances of this pattern.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Message-id: 20200214171712.541358-4-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
| -rw-r--r-- | block.c | 5 | ||||
| -rw-r--r-- | chardev/spice.c | 4 | ||||
| -rw-r--r-- | include/qemu/queue.h | 14 |
3 files changed, 16 insertions, 7 deletions
@@ -2636,10 +2636,7 @@ BdrvChild *bdrv_attach_child(BlockDriverState *parent_bs, static void bdrv_detach_child(BdrvChild *child) { - if (child->next.le_prev) { - QLIST_REMOVE(child, next); - child->next.le_prev = NULL; - } + QLIST_SAFE_REMOVE(child, next); bdrv_replace_child(child, NULL); diff --git a/chardev/spice.c b/chardev/spice.c index 241e2b7770..bf7ea1e294 100644 --- a/chardev/spice.c +++ b/chardev/spice.c @@ -216,9 +216,7 @@ static void char_spice_finalize(Object *obj) vmc_unregister_interface(s); - if (s->next.le_prev) { - QLIST_REMOVE(s, next); - } + QLIST_SAFE_REMOVE(s, next); g_free((char *)s->sin.subtype); g_free((char *)s->sin.portname); diff --git a/include/qemu/queue.h b/include/qemu/queue.h index fcecb70228..60e794a4e3 100644 --- a/include/qemu/queue.h +++ b/include/qemu/queue.h @@ -144,6 +144,20 @@ struct { \ *(elm)->field.le_prev = (elm)->field.le_next; \ } while (/*CONSTCOND*/0) +/* + * Like QLIST_REMOVE() but safe to call when elm is not in a list + */ +#define QLIST_SAFE_REMOVE(elm, field) do { \ + if ((elm)->field.le_prev != NULL) { \ + if ((elm)->field.le_next != NULL) \ + (elm)->field.le_next->field.le_prev = \ + (elm)->field.le_prev; \ + *(elm)->field.le_prev = (elm)->field.le_next; \ + (elm)->field.le_next = NULL; \ + (elm)->field.le_prev = NULL; \ + } \ +} while (/*CONSTCOND*/0) + #define QLIST_FOREACH(var, head, field) \ for ((var) = ((head)->lh_first); \ (var); \ |